Broadcasting from the rebuilt Pentagon, show co-host Charles Gibson pressed Rumsfeld on the "evidence" of Saddam Hussein's chemical, biological and nuclear programs.

"(Saddam Hussein) certainly has chemical and biological weapons," Rumsfeld said. "He's used chemical weapons against his own people and against his neighbors."

Iraq used chemical weapons during its near-decade-long war with Iran in the 1980s. Saddam Hussein also used chemical agents against dissident populations within Iraq. He threatened to use such weapons against the coalition opposing his invasion of Kuwait in 1990, but he did not use them.

Rumsfeld said that with the absence of U.N. inspectors inside the country, information about Iraq's nuclear program "is not knowable." But Iraq's hunger for these weapons is knowable, he said.

Prior to the Persian Gulf War, the best estimates for Iraq developing a nuclear weapon was between two to six years, Rumsfeld said. "When the Gulf War ended, we were able to look where he was and it turned out he was within six to 12 months of having a nuclear weapon," he said. "You know (the Iraqis) are getting closer every day, every week, every month and therefore, time is not on your side."

Gibson asked the secretary what "direct evidence" the United States has that Saddam Hussein is pursuing nuclear weapons. Gibson cited Adlai Stevenson presenting aerial photos of Soviet missiles in Cuba to the United Nations in 1962 as an example of the type of evidence. Rumsfeld said the evidence is there and that President Bush would make his case to the American people and the United Nations Sept. 12.

"The idea of direct evidence sounds like a court of law under Article III of our Constitution where your goal is to punish somebody for doing something wrong," Rumsfeld said. "But that really isn't the case here. This is self-defense. The U.S. task is to see that we don't allow an event to happen that we then have to punish someone for."

Rumsfeld cited a number of examples of after-the-fact books and investigations. He listed John F. Kennedy's book "Why England Slept" on why Great Britain didn't confront Hitler earlier. He talked about the Pearl Harbor investigations looking at intelligence failures on Dec. 7, 1941. And he spoke about the congressional investigations seeking to "connect the dots" on intelligence matters before Sept. 11, 2001.

"What do those pieces of information mean?" he asked. "What might we have done before the attack (to prevent the attacks)? The task today is to connect those dots before a weapon of mass destruction is used against the West."

Rumsfeld said the situation in Iraq and Iran is basically different. He said there is a potential in Iran for a regime change without outside influence. No such chance exists for Iraq. "The regime in Iraq is so repressive, there isn't any likelihood that it could be done from within," he said.

"Good Morning, America" highlighted the rebuilt Pentagon in its broadcast. News crews visited areas destroyed in the attack, spoke with survivors and construction people who participated in Project Phoenix. Rumsfeld said when he saw the devastation of Sept. 11, he would not have expected the Pentagon would be rebuilt and occupied by the first anniversary of the attack.

"It never would have crossed my mind that they could do it that fast," he said to Gibson. "Of course, we never did stop working here. The bulk of the building kept going. The major sections (at the attack site) were not functional."

He said the construction crews "have done a brilliant job. They've worked their heads off. It was important to them, and they did it. They've accomplished an amazing thing."